Process for the production of alkali metal perborates

ABSTRACT

This invention is directed to a process for preparing alkali metal perborates and may take the form of various embodiments in which hydrogen peroxide is formed in organic solution and reacted with borate. In one embodiment a single reaction step is used wherein an organic compound containing at least two hydrogen atoms capable of being oxidized to hydrogen peroxide is reacted with oxygen in an organic solvent and in the presence of solid alkali metal borate and water wherein the organic solvent is a solvent for the water and the organic compound but not for the alkali metal borate and perborate. In another embodiment the hydrogen peroxide is formed in an organic solvent as described above and subsequently reacted with alkali metal borate in the presence of water in an amount of from more than 1 mole to 5 moles at a temperature of 10*-60* C. In another embodiment the one or two step processes are conducted using less than one mole of alkali metal borate per gram atom active oxygen present or theoretically obtainable from the said organic compound. The process may be conducted wherein the water content is regulated according to the inequalities defined in the claims and utilizing sodium metaborate or disodium tetraborate or mixtures thereof.

United States Patent Till [451 Mar. 21, 1972 [54] PROCESS FOR THEPRODUCTION OF ALKALI METAL PERBORATES [72] Inventor: Heinrich Till,Tyrol, Austria [63] Continuation-impart of Ser. No. 594,988, Nov. 17,1966, abandoned, Continuation-in-part of Ser. No. 753,763, Aug. 19,1968, abandoned, Continuation-inpart of Ser. No. 837,983, May 15, 1969,abandoned, Continuation-in-part of Ser. No. 551,537, May 20, 1966,abandoned.

[ 30] Foreign Application Priority Data May 20, 1965 Austria ..A 4586/65July 14, 1966 Austria ..A 10310/66 FOREIGN PATENTS OR APPLICATIONS540,130 8/1955 Belgium ...23/60 1,367,499 6/1964 France... ...23/601,498,350 9/1967 France... .23/60 1,504,848 10/1967 France ...23/60925,587 5/1963 Great Britain... ..23/60 Primary Examiner-Herbert T.Carter Attorney-Stevens, Davis, Miller & Mosher [57] ABSTRACT Thisinvention is directed to a process for preparing alkali metal perboratesand may take the form of various embodiments in which hydrogen peroxideis formed in organic solution and reacted with borate. In one embodimenta single reaction step is used wherein an organic compound containing atleast two hydrogen atoms capable of being oxidized to hydrogen peroxideis reacted with oxygen in an organic solvent and in the presence ofsolid alkali metal borate and water wherein the organic solvent is asolvent for the water and the organic compound but not for the alkalimetal borate and perborate. In another embodiment the hydrogen peroxideis formed in an organic solvent as described above and sub sequentlyreacted with alkali metal borate in the presence of water in an amountof from more than 1 mole to 5 moles at a temperature of l060 C. Inanother embodiment the one or two step processes are conducted usingless than one mole of alkali metal borate per gram atom active oxygenpresent or theoretically obtainable from the said organic compound. Theprocess may be conducted wherein the water content is regulatedaccording to the inequalities defined in the claims and utilizing sodiummetaborate or disodium tetraborate or mixtures thereof.

33 Claims, No Drawings PROCESS FOR THE PRODUCTION OIF'ALKAILII METALPERBORATIES This application is a continuation-in-part of our copendingapplication Ser. No. 594,988 filed Nov. 17, 1966, now abandoned;application Ser. No. 753,763, filed Aug. 19, 1968, now abandoned; andapplication Ser. No. 837,983 filed May 15, 1969, now abandoned, which isa continuation application of application Ser. No. 551,537, filed May20, 1966, now abandoned.

Sodium perborate is produced on a technical scale by reaction ofhydrogen peroxide with sodium metaborate in an aqueous solution. In thesame way other perborates can be obtained. The necessary aqueoussolutions of hydrogen peroxide are obtained by electrolytic or organicprocesses, among which the anthraquinone process" is the bestknown. Thereaction of borates with hydrogen peroxide of electrolytic origin. isoften effected already in the same anode chamber in which the hydrogenperoxide is produced. The organic processes have increasingly replacedthe electrolytic ones.

The production of hydrogen peroxide according to the organic processesare based upon a simple chemical principle. It has been long known thatnumerous organic compounds form hydrogen peroxide with molecular oxygen.In the following description such compounds are called autoxidants. Thesocalled anthraquinone process" uses alkyl anthrahydroquinones, whichwhen reacted with oxygen yield hydrogen peroxide and the correspondingalkyl anthraquinones. These are again reduced on a catalyst by hydrogento the hydroquinone. The following oxidation with oxygen again produceshydrogen peroxide to complete the cycle.

The alkyl anthrahydroquinonesare only intermediate products andessentially only the combination between oxygen and hydrogen toformhydrogen peroxide results. It is,

however, not necessary to build up a cyclic process for production ofhydrogen peroxide using the organic synthesis. For instance the reactionbetween oxygen and isopropanol gives hydrogen peroxide and acetone. Thelatter can be hydrogenated again or otherwise used, for instance put onthe market. The chemical principle indeed is simple, but common to allthe organic processes it is a fact that the hydrogen peroxide isproduced in a very dilute organic solution and this dilute solution mustbe converted to a concentrated aqueous solution of hydrogen peroxide.This leads to technological difficulties which determine the costs ofthe technical process.

To obtain the hydrogen peroxide from the diluted organic solutions thesemust be extracted or distilled. Both of these methods lead toconsiderable losses of hydrogen peroxide; in addition the finallyrecovered aqueous solutions have to be purified. The extraction is onlythen economical when the distribution relation between the organicsolution and water is such that the water takes up the organiccomponents poorly and the hydrogen peroxide very well. This requirementpermits for the technical process only certain solvents which actuallymay not be suitable for the process for other reasons, for instancebecause of the solvent power for the autoxidant or the high costs. Thedistillation is accompanied by a great danger of explosion and requiresgreat security precautions and much heat energy.

The present invention relates to processes for the production ofperborates, in which the circuitous method involving aqueous hydrogenperoxide solutions is avoided by extracting hydrogen peroxide with solidborates from diluted organic solutions. Under suitable reactionconditions one can, compared with the conventional technical processesfor perborate production and in addition to the mentioned simplificationof the process, avoid losses of hydrogen peroxide and the purificationof its aqueous solutions, choose solvents independent of thedistribution relations between organic solutions and water, avoid thedanger of explosion and save heat energy.

In French Pat. No. 1,367,499 a process for the production of sodiumperborate is disclosed in which at first an organic solution of freehydrogen peroxide is prepared and is then reacted with solid sodiumborates with the addition of small amounts of water. The principle ofthis proposed process, however, is inferable from the reported attemptsthat have been undertaken, within the framework of the anthraquinoneprocess of hydrogen peroxide production, to eliminate residual hydrogenperoxide, which cannot be extracted with water from a circulatingsolution at economic cost, by the addition of sodium metaborate and sorender it non-detrimental. In the aforementioned French patent it isstated that the amounts of water necessary are at the most 1 mole permole of hydrogen peroxide. Water in excess should only act as a dilutionmedium.

Surprising y, and in contrast to the last-described process, it has beenfound that the production process for alkali metal perborates in whichhydrogen peroxide is prepared in a predominantly organic solution, forexample by oxidation with an oxygen'containing gas of an organiccompound containing at least two hydrogen atoms which oxidize with theformation of hydrogen peroxide, the organic solution being a solvent forthe water and being a non-solvent for alkali metal borates andperborates, followed by reaction of the organic hydrogen peroxidesolution with a solid alkali metal borate in the presence of a smallamount of water, can be carried out in an economical and technicallyrewarding manner only when the reaction mixture contains more than onemole of water in relation to the amount of alkali metal borate employedand more than 1 mole of water in relation to the amount of hydrogenperoxide present. Preferably, more than 2 moles of water should bepresent in the reaction mixture in relation to the amount of alkalimetal borate employed.

Investigations into the process have proved that water plays a decisivepart in the introduction of the hydrogen peroxide into the boratecrystals. As a general rule it can be said that hydrogen peroxide inorganic solution forms the perborate with a given alkali metal borate ora given alkali metal borate hydrate all the more readily and rapidly,the greater the total amount of water in the reaction mixture. For thesuccess of the process it is not normally of any importance whether thenecessary amount of water enters the reaction mixture in the form offree water or as water or hydration, but a certain minimum concentrationof free water in the organic solution should be present, otherwise therate of reaction may be too slow, at least at the commencement of thereaction. Hydrogen peroxide which is incorporated in an alkali metalborate hydrate liberates water from it.

There is, however, an upper limit to the permissible amount ofconcentration of water. If the water content of the reaction mixture isincreased step-by-step, a gradual coarsening of the grain is observable,until finally the solid product agglomerates to form a sticky mass whichmay be difficult to remove from the reaction vessel. If theconcentration of water is not too high, the sticky masses become solidin air and can be ground. A marked coarsening of the grain alone has anadverse effect, because a proportion of the unchanged borate isentrapped in the grains which means that it is withdrawn from thereaction or requires a disproportionately long time for reaction. If theprogressive coarsening of the grain goes too far, traces of solvent areoccluded which are difficult to eliminate when the solid product iswashed. The residue of such enclosed material that remains in the finalproduct is not significant in weight, but it discolors the perborate,with the result that it does not form completely clear solutions inwater and decomposes more readily then otherwise.

In order to obtain the greatest possible amount of perborate from agiven volume of reaction solution per unit of time or per charge, theautoxidant selected must be employed in the highest practicableconcentration. It has been found that solvents which have gooddissolving power for the autoxidants used generally require much waterfor providing optimal reaction proceedings. This circumstance brings amost important advantage for the process; only now it is possible to usea solvent with good dissolving power. With solvents which are It isnecessary that the boron compounds are present during the reaction inthe crystalline form. In this case and if the amount of water is not toohigh, absorption of organic substances by the reaction product can beavoided or takes place only in such manner that the organic impuritiescan easily be washed out by organic low boiling solvents. If onesuspends alkali metal borates in organic hydrogen peroxide solutionswhich are able to dissolve a substantial part of the borate, one obtainsperborates indeed, but these are inferior with respect to purity, colorand stability. The used solvents or mixtures of solvents shouldtherefore be non-solvents for the alkali metal borate and also for theresulting perborate. The use of the termnon-solvent" does not excludesolvents which take up traces of borate which are taken up by everysolvent. It is not advisable to work with solvents which require forgood results more than 5 moles of water per mole of alkali metal borate.Such solvents are so strongly polar that they would dissolve togetherwith the relatively high amount of water too much borate so that thementioned disadvantages would be obvious. Preferably more than 2 and upto 5 moles of water in relation to the employed mole amount of alkalimetal borate should be used. If sodium metaborate is employed it isespecially advantageous to use from 2 to 4 moles water per mole NaBOFree water generated during the reaction must be dissolved by theorganic solution, i.e., there must not be formed a stable aqueous layer.In the latter case the yield would be small and purity, color andstability of the resulting products would not be satisfactory. Theorganic solvents of the reaction mixtures must therefore be solvents forthe water.

The preferred alkali metal borate is sodium borate, especially sodiummetaborate. If it is intended to obtain in one reaction step about 1gram atom of active oxygen per mole of the employed solid alkali metalborate, then 0.95-1.2 moles of alkali metal borate per mole of hydrogenperoxide is employed. A greater excess of borate makes it possible torecover the existing hydrogen peroxide from the organic solution in aparticular good yield. One obtains a product with a relatively lowcontent of active oxygen indeed, but it is possible to react this oncemore, as is mentioned below. If one uses less borate it is possible toobtain higher contents of active oxygen in the final product, but thehydrogen peroxide present in the organic solution is then not so wellexhausted. Commonly 0.8 to 2.0 moles of alkali metal borate per mole ofthe hydrogen peroxide present is employed.

Increasing of temperature leads to an acceleration of the reaction andto an increase of the solvent power of the employed solvents for theautoxidants. There are, however, limits for the temperature. Attemperatures above 60 C. during the reaction with the alkali metalborates decomposition occurs which reduces the economics of the process.Therefore, it is preferred to work at to 60 C.

Examples of especially suitable compounds, containing at least twohydrogen atoms which oxidize with the formation of hydrogen peroxideautoxidants are hydroquinones, especially anthrahydroquinone whichcontains alkyl groups with one to six carbon atoms. Other especiallysuitable autoxidants are hydrazo compounds, particularly hydrazobenzene,aminophenols and secondary alcohols, such as cyclohexanol. The oxidationis effected with molecular oxygen, i.e., air, or other gaseous mixturescontaining molecular oxygen. Some autoxidants form hydrogen peroxidewith oxygen only at higher temperatures, for instance the secondaryalcohols considerably above 60 C. In such cases the oxidation mixturemust be cooled before reaction with the alkali metal borate.

Suitable solvents for the autoxidants include alcohols with from four to12 carbon atoms, e.g., Z-ethylhexanol, esters of aromatic carbonic acidswith methanol e.g., phthalic acid dimethylester, acetic acid esters ofcyclohexanol and of its substituted derivatives, ketones having fromfive to 12 carbon atoms and alkyl groups-substituted benzenes andnaphthalenes. The mentioned aromatic hydrocarbons are preferably used inmixtures, because they themselves dissolve the autoxidants poorly on theone hand and decrease on the 4 other hand the polarity and accordinglythe solvent power for borates or other solvents.

The autoxidants may themselves act as a the cyclohexanol is used.

When reacting an alkali metal borate with a hydrogen peroxide containingorganic solution without further measures, the total content of water inthe reaction mixture remains constant during reaction. Accordingly,depending upon whether the borate is employed in the hydrate ornonhydrate form, as a rule the water content of the solid will fall andthe concentration of the dissolved water in the organic solution willincrease or vice versa.

If an inert gas is passed through the reaction mixture, it is possibleby suitable choice of the moisture of the gas to add or to remove waterrespectively by this expedient during the reaction, thereby making itpossible to regulate the water concentration in the organic solutionduring the reaction. It is possible to obtain the perborate product inparticularly high yields and with particularly good properties (i.e., ina powdery to granular form) and with a high reaction velocity if thewater concentration in the organic solution, starting from the beginningof the reaction adjusted figures, is kept just so high during thereaction, that no agglomerations of the solid occurs and if the waterconcentration is lowered, if desired, only so far that formedagglomerations will thereby dissolve again. The agglomeration of thesolid is usually easily observed and the water concentration is thenregulated corresponding according to the observations by changing theamount or the water partial pressure of the inert gas passed through thereaction mixture.

The so far described methods as is the process of the previouslymentioned French Pat. No. 1,367,499 are concerned with process conductedin two stages: first the hydrogen peroxide is prepared in the organicsolution and then the oxidation mixture is reacted with the alkali metalborate.

It has now been found that alkali metal perborates can be produced in asingle reaction step when an organic compound which contains at leasttwo hydrogen atoms oxidizable with formation of hydrogen peroxide isoxidized by an oxygen-containing gas in an organic solvent or in amixture of organic solvents in the presence of a solid alkali metalborate and in the presence of water, the organic solvent or the mixturebeing a solvent for the water and the organic compound, but a nonsolventfor the alkali metal borate and the perborate. For example, sodiummetaborate is suspended in the form of its hydrate or non-hydrate in asolution of an autoxidant and the suspension is oxidized with molecularoxygen, preferably air. At the end of the reaction period the length ofwhich may be longer than but which depends upon the oxidation time ofthe autoxidant, the solid is filtered or centrifugated, washed with asuitable solvent and dried. This process is more economical than theabove described two-stage process.

Use of the one-step process leads to substantial simplifications in thenecessary apparatus. By concurrently conducting the oxidation and thereaction of the formed hydrogen peroxide with the alkali metal borate awhole stage of the process is eliminated. Moreover, the considerableamounts of oxygen containing gas which have to be passed through thesuspension can efi'ect totally or at least to a substantial part thestirring which is necessary for the reaction with the alkali metalborate. Stirrers which would be necessary if a separate stage for thereaction with the borate were retained, are now unnecessary or at leastonly needed in a more simple form. Furthermore, the total reaction timeis reduced because the perborate formation takes place during theoxidation. The oxidation is assisted by the presence of borate orperborate.

In the one-step process the total yield in relation to the autoxidantemployed is also higher. During the oxidation in the two-step processthere occur losses of hydrogen peroxide or active oxygen. These lossesresult partly from the fact that already formed hydrogen peroxide reactswith the autoxidant, e.g., 2-ethylanthrahydroquinone not yet reacted,and partly solvent, e.g., when from the fact that impurities introducedinto the solution which have catalytic activity lead to decomposition.If the active oxygen produced by the oxidation is fixed at once byformation of solid perborate, the concentration of hydrogen peroxide inthe solution remains low during the total reaction and both the reactionwith the autoxidant and the decomposition become negligible.

Further advantages of the one-stage process as compared to -thetwo-stage process are realized in connection with the amounts of waterwhich must be present in the reaction mixture so that the formation ofthe perborate occurs at a satisfactory velocity, and the perborate isproduced in high yield and with good properties. The above discussionregarding the function of the water upon the incorporation of thehydrogen peroxide in the borate crystals is also valid here. Generally,it is desired to recover the perborates in a powdery or granular form.

Preferably alkali metal borate hydrates are employed in the processbecause these are easy to produce. Anhydrous alkali metal borates canonly be prepared from'their hydrates with a necessarily higherexpenditure for apparatus and production of heat energy.

When hydrogen peroxide is incorporated in a borate hydrate, usually acertain amount of water of crystallization is set free, which, ofcourse, is larger when the amount of water of crystallization in theborate employed is large. The water concentration in the organicsolution is increased by the freed water, whereby the further perborateformation is accelerated thus again leading to liberation of water ofcrystallization. In thisway the effect of the water often-exceeds thedesired acceleration of the-perborate formation and leads to asubstantial sticking together of the solid. Thus the reaction proceeds vso slowly with a su spension of sodium'metaborate dihydrate (NaBQ 2H- O)in some solutions having a low water content,

the autoxidant content of which is already totally oxidized, that. anoperation on a technical scale is not feasible. Analogous experimentswith slightly wetted, but otherwise similar solutions produce, however,quick reactions but also a total sticking together of the solid.

With the employment of hydrate mixtures of sodium metaborate, whichcontain on an average more water then the dihydrate, this difficultyoccurs particularly often and markedly. The situation with the otheralkali metal borate hydrates is similar. Therefore there are cases inwhich in the two-stage process the reaction products cannot be obtainedin a powdery or granular form without regulating the water concentrationin the organic solution with the help of an inert gas. The one-stageprocess is here, however, successful. While in the two-stage process thehydrogen peroxide in the beginning of the reaction with the alkali metalborate hydrate is present in a particularly high concentration, and thereaction once started proceeds particularly quickly and therefore thedanger of local high concentrations of water and corresponding increasedtendency toward sticking exists, in the one-stage process the totalhydrogen peroxide for the reaction is formed gradually during theoxidation. High concentrations of water do not occur and the tendencytoward sticking together is much lower.

Lastly it is possible in contrast to the two-stage process to use theoxidizing gas, e.g., air, also for the purpose of regulating the waterconcentration in the organic solution during the reaction.

Autoxidants which are suitable for the two-stage process can usually beemployed for the one-stage process too. Exceptions are these autoxidantswhich can be oxidized only at relatively high temperatures, i.e.,substantially above 60 C. with formation of hydrogen peroxide. Secondaryalcohols can therefore not be used for the one-stage process.

The other conditions of the one-stage process are similar to thetwo-stage process. In the following description where no numericalvalues are given for the one step process those of the two-step processcan be adopted. Preferably more than 2 moles of water in relation to thealkali metaborate employed should be present in the starting reactionmixture. It is here advantageous too, to use not more than 5 moles inrelation to the mole amount of alkali metal borate. it is especiallyadvantageous to employ 2 to 4 moles of water per one mole of sodiummetaborate (1411180,).

The preferred alkali metal borates are sodium borates, especially sodiummetaborate.

If it is intended to fix in the solid about 1 gram atom of active oxygenper mole of the alkali metal borate employed, there should be appliedfrom 1.0 to 1.3 moles of alkali metal borate per mole of hydrogenperoxide theoretically obtained from the autoxidant. Usually 0.6 to 2.0moles of alkali metal borate per 1 mole of theoretically obtainablehydrogen peroxide are employed. If only minimal sticking of the solidduring the reaction is wanted, the water concentration adjusted at thebeginning of the reaction in the organic solution should be held nearlyconstant. This can be effected in the above mentioned manner by the gaspassed for oxidation through the solution. It is, however, possible toobtain the perborate product with especially high yield, especially goodproperties, i.e., in powdery to granular form and at a high reactionrate, if the water concentration in the organic solution, starting fromthe adjusted figure at the beginning of the reaction, is kept a littlelower than the concentration at which an already substantial coarseningof the grains begins. As seen from the outside, this coarsening of thegrains appears as agglomerations of the suspended solid. It is desirabletherefore to direct the reaction in a manner that the waterconcentration remains so high that no agglomeration of the solid occurs,and that the water concentration in a given case is lowered so far thatthe formed agglomerations just redissolve again. The water concentrationcan be regulated in response to the visual observation by changing theamount of. water partial pressure of the gas passed through the reactionmixture.

Perborates are used for the production of detergents and bleachingagents. The purpose of fixing hydrogen peroxide and active oxygen to theborates is to convert these to a solid form. This solid active oxygencontaining product can then be added to solid detergents and bleachingagents. In the perborates the active oxygen is the technically mostinteresting component, the containedborate being only a ballast. Thisballast is very expensive and in addition is poisonous. Commercially,until now, all sodium perborate contains per mole of sodium metaborate(N21130:) at most 1 mole of hydrogen peroxide or 1 gram atom of activeoxygen.

There is known a process of producing alkali metal perborates whichcontain per mole of the employed borate more than 1 mole of hydrogenperoxide or more than 1 gram atom of active oxygen. In this process theborate is evaporated to dryness with a great excess of aqueous hydrogenperoxide under reduced pressure. Operations such as this, however, arehazardous and expensive owing to the pronounced tendency todecomposition of the hydrogen peroxide. These perborates have hithertobeen only of scientific interest.

It has now been found that alkali metal perborates can be obtained whichcontain more than 1 gram atom of active oxygen per mole of the startingborate, if nonaqueous organic solutions of hydrogen peroxide are reactedwith solid alkali metal borates and a deficiency of borates is employedin relation to the hydrogen peroxide or the autoxidant. Here also thereaction of the alkali metal borate has to take place in the presence ofwater though in small amounts the organic solution must be again asolvent for the water and a non-solvent for the alkali metal borate andthe resulting perborate. The necessary organic solutions of hydrogenperoxide are obtained in a favorable manner by oxidizing an organiccompound, which contains at least 2 hydrogen atoms which oxidize to formhydrogen peroxide, in a solution of an organic solvent or a mixture oforganic solvents by an oxygen-containing gas. Lastly it is possible touse the one-stage and the twostage processes as they have been describedabove. The alkali metal perborate products obtained following the justdescribed method consist usually not of a single compound but of amixture of different perborate compounds which sometimes containresidues of the starting borate. lf, e.g., sodium metaborate has beenemployed, the resulting sodium perborate containing mixtures containmore than 1 gram atom active oxygen per mole of NaBO, on an average andsatisfy the condition of containing active oxygen together with aslittle as possible of expensive and toxic boron in solid form.

If for instance disodium tetraborate is employed as the starting borate,according to known processes which use aqueous solutions of hydrogenperoxide, 1 mole of hydrogen peroxide is incorporated in 1 mole disodiumtetraborate, i.e., to 4 gram atoms of boron and so results in arelatively great amount of ballast. Until now and despite its easyavailability and lower price compared with the metaborate per unit ofboron, disodium tetraborate has not become important as a startingmaterial for the production of perborates. If disodium tetraborate isemployed in the process of this invention a perborate product isobtained in an economical manner. Surprisingly the action of excessivehydrogen peroxide contained in organic solvents liberates boric acidfrom the disodium tetraborate which dissolves totally or partly.Disregarding the content of water of crystallization, the processes canbe written as follows:

2 Nasog'Hgoz "202 2 H202 H The boron trioxide does not accumulate as theoxide but as meta or orthoboric acid depending upon the existing waterconcentration. Starting from disodium tetraborate there can be preparedperborate products in which the ratio (gram atom of active oxygen) (gramatom of boron) lies above 0.25 by a greater amount, the greater theexcess of hydrogen peroxide. Besides the sodium perborate mixture, boricacid is obtained as an additional very valuable product, which can berecovered in a, per se, known manner by shaking out with water from thereaction solution. This, together with the mentioned fact that disodiumtetraborate is a very favorable starting product, leads to theeconomical production of perborate products which have a ratio (gramatom of active oxygen) (gram atom of boron) smaller than 1.

There can be employed also other alkali metal polyborates like disodiumtetraborate with the same result. In any case according to the inventionalkali metal perborate-containing mixtures are obtained which contain asan average more than 1 gram atom of active oxygen per n gram atom ofalkali metal, n being the basicity of the boric acid on which thestarting borate is based.

As starting borates there can be employed also alkali metal perboratesor mixtures of alkali metal perborates and alkali metal borates with alower content of active oxygen as desired. In this way it is possible toproduce perborate containing products with especially large content ofactive oxygen.

lf according to the invention alkali metal borates are added in lessthan molar amounts to the hydrogen peroxide in organic solution,perborates or mixtures of perborates are formed which contain per moleof the starting borate more than 1 gram atom of active oxygen. It is,however, possible to stop the reaction in a short time in which caseproducts are obtained which contain, e.g., only 1 gram atom of activeoxygen per mole of the starting borate. Such a procedure is advantageouswhen it is desired to prepare perborate mixtures of different content ofactive oxygen or frequently changed content.

Even if reactions using a deficiency of alkali metal borates are reacteduntil the end of the reaction, the yield in relation to the autoxidantor the hydrogen peroxide employed is lower then with reactions which areconducted with an equimolar amount or an excess of alkali metal borate.In such cases there remains after the separation of the perborateproducts an organic solution which yet contains considerable amounts ofhydrogen peroxide, and indeed the amount is larger when the amount ofalkali metal borate that has been employed is smaller in relation to theautoxidant or hydrogen peroxide and the earlier the reaction has beenstopped. It is possible to react the still remaining hydrogenperoxide-containing organic solution a second time with an excess ofalkali metal borate in the manner described above and obtain withextensive utilization of the residual hydrogen peroxide a product poorerin active oxygen. If this is added as the starting borate to the firstreaction, i.e., an excess of hydrogen peroxide, the advantage of anespecially complete utilization of the autoxidant employed or thehydrogen peroxide employed can be combined with the advantage of theproduction of perborate products of especially high content of activeoxygen.

The advantages derived from working with a deficiency of alkali metalborate become apparent if 0.9 mole or less alkali metal borate per moleof hydrogen peroxide present or theoretically derivable from theautoxidant is employed. If less than 0.1 mole alkali metal borate areused the yield is so small that the process cannot be conductedeconomically. Preferably more than 0.1 and less than 0.6 moles of alkalimetal borate per mole of hydrogen peroxide present or theoreticallyderivable from the autoxidant is employed.

Also in reactions with a deficiency of alkali metal borate the preferredborates are sodium metaborate and desodium tetraborate.

In reactions with a deficiency of alkali metal borate the water playsalso an important part in the incorporation of the hydrogen peroxide inthe borate crystals. if high yields and a final product having as highas possible a content of active oxygen is desired, the water content inthe reaction mixtures has to be properly regulated.

If sodium metaborate is the starting borate in a one-stage process atthe beginning of the reaction from 1.5 to 4 moles water should beemployed per mole of hydrogen peroxide theoretically obtained from theautoxidant. In a two-stage process 1.5 to 4 moles of water per mole ofhydrogen peroxide present in the oxidation mixture of the startingreaction mixture should be employed.

If disodium tetraborate is used as the starting borate, in the one-stageprocess the starting reaction mixture should contain from 2.5 7 moles ofwater per mole of hydrogen peroxide theoretically obtainable from theautoxidant; in the two-stage process there should be employed 2.5 7moles of water per mole of the hydrogen peroxide which is present in theoxidation mixture of the starting reaction mixture.

It is especially advantageous to correlate the water concentration W[mole/kg] in the organic solution of the starting reaction mixtures withthe saturation concentration of the water in the corresponding organicsolution at the specified reaction temperature. The organic solutionsconsist as a rule chiefly of an organic solvent or a mixture of organicsolvents and of the autoxidant or its oxidation product. Besides thisthe organic solutions contain small amounts of water and moreor-lesshydrogen peroxide. The saturation concentration of the water in theorganic solution W, [mole/kg] has to be determined in the one-stageprocess at a time at which it contains the autoxidant but no hydrogenperoxide. In the twostage process the saturation concentration W,[mole/kg] in the organic solution has to be determined at that state atwhich the solution contains the oxidation product of the autoxidant butno hydrogen peroxide. For the water concentration W the water ofcrystallization content of the starting borate K plays an importantpart. This figure is ordinarily defined as mole of water per mole ofstarting borate, e.g., [mole H O/mole NaBO or [mole H O/mole Na B O Ifan alkali metal perborate or a mixture of alkali metal perborates andborates is employed with a smaller (as desired) content of active oxygenas the starting borate, K means the average content of water ofcrystallization of this starting borate, in relation to thestoichiometrically present sodium metaborate [mole H O per mole NaBo Inthe one-stage process and when sodium metaborate is employed W should beselected according to the inequalities In this u means the ratio betweenthe moles of sodium metaborate employed and the moles of hydrogenperoxide theoretically obtainable from the autoxidant in the startingreaction mixture.

In a one'stage process and when disodium tetraborate is employed Wshould be selected according to the inequalities [B] K W K W T6 5 W05 T6In a one-stage process and if a mixture containing sodium perborate witha'lower content of active oxygen is employed as the starting borate thewater concentration W should be selected according to the inequalities[C] 2 K' (3u 10.7H+ 2 10 u means the ratio between the moles of sodiummetaborate, (NaBO,) which are stoichiometrically.contained in thestarting sodium perborate containing mixture and the sum of moles whichconsists of the hydrogen peroxide or active oxygen which are alreadyincluded in the starting perborate containing mixture and that which canbe theoretically obtained from the autoxidant employed. H means theaverage content of active oxygen in the employed sodium perboratecontaining mixture in relation to the sodium metaboratestoichiometrically contained in the starting sodium perborate containingmixture [gram atom of active O/mole NaBO In a two-stage process and whensodium metaborate is employed, W should be selected according to theinequalities i A K W,

In a two-stage process and if a sodium perborate containing mixture witha lower content of active oxygen is employed as the starting borate thewater concentration W should be selected according to the inequalities[f] u means herein the ratio between the moles of stoichiometricallycontained sodium metaborate (NaBO in the starting sodium perboratecontaining mixture and the sum of moles which consists of the hydrogenperoxide or active oxygen already contained in the starting perboratecontaining mixture mixture of the starting reaction mixture. Also, Hmeans the average content of active oxygen in the sodium perboratecontaining mixture in relation to the sodium metaborate It should bepointed out that also in processes which work stoichiometricallycontained in the starting sodium perborate containing mixture [gram atomactive O/mole NaBO especially with a deficiency of alkali metal boratethe conditions are generally the same as they were described for theoneand two-stage processes. It is therefore also of particular advantagein the one-stage process to regulate the water concentration in theorganic solution during the reaction by means of the oxygen containinggas passed through the reaction mixture, and in the two-stage process byan inert gas passed through the reaction mixture. As described above theamount and the content of water vapor should be regulated so high thatjust no agglomeration of solid occurs or formed agglomerations justdissolve again in all processes described here it is advantageous afterseparation of the final perborate product and possibly after repeatingthe reaction, to convert the remaining solution by, per se,1656155666631; processesinto a solution for use again in the describedprocesses if desired after recovering several byproducts. The processcan also be conducted continuously, e.g., in a cascade of stirredvessels.

The more powdery the employed alkali metal borates are and the more careone uses in adding the solid to the solution in as good distribution aspossible, the greater is the yield at a given reaction time. Onprinciple the described reactions proceed with coarse material too, butthen the reaction time is exclusively determined by diffusion and thereactions become uneconomical because of very long reaction times. Aspecific definition concerning the size of the granules cannot bestated. In general it is advantageous to prepare the starting alkalimetal borates so that they do not contain particles bigger than 300p.and have an average particle diameter smaller than When using a doublereaction, e.g., to obtain a perborate product with an especially highcontent of active oxygen and to realize an especially good. utilizationof the employed autoxidant or, the employed hydrogen peroxide, andintermediate grinding of the solids that are still poor in active oxygenafter the first reaction is highly recommended.

The present invention is further illustrated by the following examples.In the examples the parts mentioned are parts by weight and thetemperatures are in degrees centigrade. Where gases are forced throughthe reaction mixtures, these gases prior to their introduction into thereaction vessels are substantially loaded with the vapor of the solventor solvent mixture of the organic solution so as to substantiallycorrespond to the partial pressure of the solvent above the reactionmixture involved.

EXAMPLE 1 Solutions of 2-ethyl-, 2-tert.butyl-anthrahydroquinone and ofa mixture of the isomeric Z-amyIanthrahydroquinones were prepared bydissolving the corresponding 2-alkylanthraquinones in the desiredsolvent or mixture of solvents and hydrogenating it in the presence ofpalladium precipitated on aluminum oxide with anhydrous hydrogen at 30to 50 C. Not all of the Z-alkylanthraquinone contained in the solutionwas reduced. After reaching the desired degree of hydrogenation thesolution was filtered until it was free of the catalyst, and thefiltrate was stored under pure nitrogen until used. The filtratescontained throughout less than 0.05 moles of water per kg. solution. Thesolutions thus obtained are hereinafter called the starting solutions."

Fundamentally it would be possible to use the by the alkyl substituentgroups which have not other substanand that hydrogen peroxide which ispresent in the oxidation.

tial influence on the further use of the obtained solutions.

Therefore it is possible to use other than the expressly men- 'tionedalkyl anthrahydroquinones with the same success.

EXAMPLE 2 For the preparation of solutions of 2-alkylanthrahydroquinoneswith a higher content of water the starting solutions of example 1 werestirred violently in a special vessel below pure nitrogen with thenecessary amount of water until this had been dissolved completely bythe organic solution.

EXAMPLE 3 Utilizing the two stage process, M parts of an oxidized andwetted "starting solution" prepared according to example 3 Solvent:mixture of 25 parts by weight Shellsol AB". an aromatic fraction with BP180 220C., and 75 parts by weight 2-ethyl-hexanol-l Original autoxidant:2-tert.-butylanthrahydroquinone;

EXAMPLE The two stage process was conducted in the manner of examples 4a-h with the difference that instead of sodium metaborate, powderypotassium metaborate was employed.

was introduced into a vessel with a stirrer, which was thermo- 5Temperature. 40C. statically controlled at a temperature of 8 C. Thesolution M:1450;so=0 l86;e=0 340;w0=0 462 contained s moles of hydrogenperoxide, w moles of water A =68; "10:834; K=2 15; and e moles of2-alkyl anthraquinone per kg. and had been =40 prepared from h moles ofZ-alkyI-anthrahydroquinone per kg. SE 9 To A P of P y Sodium metabol'atey- 1 P= 71; m 7.88; x= 3.55 (0.45 gram atom act. O/gram atom sisfigures: m gram atoms of Na/kg., corresponding K moles Na) water ofcrystallization per mole of NaBO were added; the u 1 05 l N ,B O.,/ o|eH 0, intensity of stirring was regulated so that the solid was divided 451 l l-l o/ le N B O, homogeneously in the liquid. 4.74 mole H olmole H0 After I minutes the reaction mixture was filtered. The 111- yield 93.5percent fthe theory in relation to H 0 trate contained s moles ofhydrogen peroxide per kg. The EXAMPLE 7 solid was washed several timesin benzene and subsequently liberated from adsorbed residues of benzeneby a short The oxidation apparatus was a cylindrical glass vessel. Thevacuum treatment. bottom had numerous fine holes through which gaseousox- The P parts of the produce contained m gram atoms of ygen could beforced. The exit gas after permeating the liquid sodium andx gram atomsof active oxygen per kg. 4 layer passed through a reflux condenser inwhich the con- The values for the various symbols set forth above andthe densable parts were condensed. The apparatus was almost resultsobtained in these examples 4 a-h are set forth in the completelysubmerged in the reaction chamber in a therfollowing Table l. mpstableglycerine bath.

TABLE I Tempera- Exsmples Solvents 2-alkylture, 6 M 11 so e W0 A 4sDlmethyl o-phthelate 2-ethyl- 20 40.51 0.187 0.183 0.422 0.427 0. 62424b -d0 ..d0..... 20 40.00 0.188 0.184 0.423 0.035 0.8100 46 ..do d0--.40 40.00 0.204 0.200 0.423 0.213 0.98%) 4d Mixture oi3perts per volumexylene isomeric ...do 20 26.25 0.148 0.146 0.300 0.130 0.2035

mlxtgtire and 4 parts per volume cyclohexyl 806 6- 4e Mixture of 1 partper volume xylene isomeric .....do 20 24.23 0.234 0.231 0.468 0.3100.4131 mixttlre and 5 parts per volume cyclohexyl ace :1 a. 4iCyclohsxyl acetate 2-tert.-butyl 40 40.00 0.180 0.176 0.400 0.080 0.963043.. .....do Z-amyl-(isomeric mixture)..- 60 100.0 0.205 0.200 0.400 0.290 1.700 4h ..d0 -.d0 60 100.0 0.205 0.203 0.400 0.090 3. 980

Yield u moles Moles Moles related NBBOz/ H 0] H10] to H10 mo K t as Pms: x H1O: NaBOz H201 (percent) 14.73 0.11 140 0.006 0.858 8. 95 8.251.04 2. 2.45 95. 5 10.00 1.90 80 0.011 0.929 8.69 7.40 1.10 2.07 2.2803.5 9. 65 2.10 100 0.008 1.000 8. 90 7.08 1. 19 3.00 3. 57 94 13.91 0.34 90 0.008 0. 405 9.04 8. 87 0. 95 1.27 1.22 93. 5 13.91 0.34 90 0.0090.643 8.89 8.25 1.03 1.65 1.70 95 7. 39 3. 86 5 0.020 0.917 7. 65 6.50 1. 00 4. 32 4.32 85 9.85 1. 99 16 0.024 0.988 8.38 8. 76 0.84 3. 533. 43 87 9.85 1.99 15 0.007 4.429 8.80 4. 1.93 2.22 4. 29 9e Theoxidation vessel was filled with 200 parts of cyclohexanol, 1 part 1.1'-dihydroxy dicyclohexyl peroxide and 0.2 parts of Victawet 35B (apolyphosphate manufactured by Victor Co., U.S.A.) were introduced intothe oxidation vessel,

(Analysis figures: m gram atoms K/kg., correspondi K 55 nd 150 liters ofundried oxygen were forced per hour and kg.

moles water of crystallization per mole KBO Solvent: cyclohexyl acetateOriginal autoxidant: 2-ethylanthrahydroquinone Temperature: 40C. m150.0; h =0.330; s 0.322; e 0.400; w 0.2 l0; A=5.l3;m =9.41;K=1.36; r 40.r,; 0.019 p= 5.46; m 8.80;x= 8. l0 v 1.00 mole KBO lmole H 0 2.01 moleH O/mole KBO 2.01 mole H O/mole H 0 yield: 91.5 percent of theory inrelation to H 0 EXAMPLE 6 A two stage process was conducted according tothe method of examples 4 a-h with the difference that instead of sodiummetaborate, powdery disodium tetraborate was employed. (Analysisfigures: m gram atoms Na/kg., corresponding K moles water ofcrystallization per mole Na B O,)

of cyclohexanol through the liquid. The reaction temperature was held at95C. When the acid content of the oxidation mixture began to risenoticeably after 6 hours, (this period may be, according to theimpurities contained in the cyclohexanol, 5 10 hours) the sum of thecontents of hydrogen peroxide and of peroxidic compounds which candissociate hydrogen peroxide under the conditions of the followingperborate formation was 0.3 moles/kg. At this time the total mixture wasplaced in a stirred vessel and cooled to 25C. Now 6.3 parts of finelydivided sodium metaborate containing water of crystallization were addedwith vigorous stirring at this temperature. This sodium metaborate hasbeen obtained from 8.27 parts NaBO,. 41-1 0 by drying at C. Afterstirring for 3 hours at the said temperature the liquid was decanted.The remaining solid was reduced to small pieces, washed with a littleethanol and dried. 8.0 parts with 9.91 percent by weight of activeoxygen were obtained.

u 1.0 mole NaBO /mole H O,

2.2 mole H o/mole NaBO 2.2 mo le l-i O/mole H 9;

EXAMPLES 8 d Using a two stage process, the oxidized and wetted startingsolution according to example 3 was reacted with solid sodiummetaborate.

A glass vessel provided with a bottom with fine holes for the passing inof nitrogen and a stirrer was thermostatically maintained at 6C. in thisvessel were placed M parts of the oxidized and wetted starting solution"containing w moles water, s moles hydrogen peroxide and e moles2-alkylanthraquinone per kg. This starting solution had containedoriginally h moles 2-alkyl anthrahydroquinone per kg. To this solution Aparts of powdery sodium metaborate (analysis figures m gram atomsNa/kg., corresponding K moles water of crystallization per mole NaB0were added. The intensity of stirring was regulated so that the solidwas divided homogeneously in the liquid at the lowest possiblestreaming,

velocity of the nitrogen. The streaming velocity was maintainedsufficiently high so that the contents of the reaction vessel did notcome out through the fine holes at the bottom of the vessel.

The streaming velocity l (liter per hour and kg. solution) and the watervapor partial pressure P,. (torr) of the nitrogen could be changed veryeasily. When the reaction proceeded so that the solid agglomerated toloose flakes, this was just countered by forcing in more dry nitrogen.Where agglomerations failed to appear or appeared only very late, waterwas brought into the reaction mixture by more wet nitrogen until flakesjust appeared which were dissolved again by lowering the amount or thewater content of the nitrogen. Conducting the process so as to be on theverge of the agglomeration, the reaction products appeared in a powderyto fine granular form; they were white and high yields were obtainedwith high reaction rates. in the place of a visual observation therecould be used a nephelometric measurement by a photocell, by which thestreaming velocity or the water vapor partial pressure P of the nitrogenand by that the water concentration of the organic solution isregulated. This has particular advantages with rapid reactions. Theregulation of the reactions and their result can be improved by settinga program for the streaming velocity or the water vapor partial pressureof the nitrogen.

. This program is established by separate experiments.

After 1 minutes the reaction mixture was filtered. The filtratecontained s moles hydrogen peroxide per kg. The solid was washed severaltimes with benzene and finally liberated from adsorbed residues ofbenzene by a short vacuum treatment.

The P parts of the product contained m gram atoms of sodium and .1: gramatoms of active oxygen per kg.

instead of nitrogen any other inert gas or inert gas mixture, e.g., aircan be used.

The values for the various symbols set forth above and the resultsobtained in these examples 8 a-d are set forth in the following TableI1:

EXAMPLE 9 A two stage process was conducted according to the method ofexamples 8 a-d with the difference that instead of sodium metaborate,finely divided potassium metaborate was employed (analysis figures: mgram atoms K/kg, corresponding K moles water of crystallization per moleK Solvent: cyclohexyl acetate Original autoxidant:Z-ethyIanthrahydroquinone Temperature: 40C. regulation by the nitrogenstream: water vapor partial pressure PM:

0 45 mm.; streaming velocity 1 500 N1 /h.kg. M 150.0; h 0.330; s 0.322;e 0.400; W 0.220 A=5.l3;m =9.4l;K= 1.36 t= 30 S 0.003 P= 5.58; m 8.59;x= 8.40 u 1.00 mole KBO /mole E 0, 2.04 mole H O/mole KBO 2.04 mole HO/mole H 0 yield 97 percent of theory related to H 0 EXAMPLES 10 a-jUsing a one step process starting solutions" of examples 1 or 2 wereoxidized in the presence of solidsodium metaborate.

Through a vessel, thermostatically controlled at 8 C. air with a watervapor partial pressure of p mm. was pumped through the fine holes in thebottom. One after the other A parts of finely divided sodium metaborate(analysis figures: m gram atoms of Na/kg. corresponding K moles water ofcrystallization per mole NaBO and M parts starting solution" from theexamples 1 and 2 were added to the vessel. The solution contained hmoles 2-alkyl anthrahydroquinone, w moles of water and e moles 2-alkylanthraquinone per kg. The charging opening of the reaction vessel wasclosed, the gas delivery pipe was combined with a rotameter and the gasvelocity set at 1 liter per hour and kg. of solution.

The sodium metaborate divided quickly in the dark solution. After Iminutes the reaction mixture was filtered. The yellow filtrate containeds moles of hydrogen peroxide per kg. The solid was washed several timeswith benzene and finally released from adsorbed residues of benzene by ashort aspiration.

The P parts of the product contained m gram atoms of sodium and x gramsatoms of active oxygen per kg.

Instead of air, other gas mixtures consisting of molecular oxygen andinert gases, and also oxygen alone can be used.

The values for the various symbols set forth above and the resultsobtained in these examples l0 a-j are set forth in the TABLE IIRegulation by the nitrogen stream Water vapor Temperapartial StreamingExamples Solvent 2-alkylture,6 pressure P veloeltyl M h 8a Diisobutylketone 2-tert.-butyl 40 0 50-400 150 0. 260 8b Dlmethyl o-phtha1ate2-ethy1- 40 0-30 700 0.244 80..-. cyclohexyl acetate 2-amy1-(isomericmixture) 60 0 60-400 100.0 0.205 8d do -.d0 60 0-70 400 100.0 0.205

Yield moles Moles Moles related NeBOr/ H20] H20] to H20 Examples so e W0A mo K 1: sm P mm 1: H2 2 N21130: H10: (Percent) 80. 0.251 0.500 0.0803.80 9.91 1.95 20 0.008 4.07 9.20 8.95 1.00 2.35 2.35 9 8b 0.242 0.5000.180 3.07 10.03 1.88 30 0.004 3.45 8.90 8.17 1.06 2.58 2.74 9 8c 0.2000.400 0.320 1.700 9.85 1. 99 10 0.018 2.023 8.26 8.90 0.84 3.90 3.27 9 d0.203 0.400 0.110 3.980 9.85 1.99 10 0.002 4.470 8.75 4.45 1.93 2.274.93 98 following Table III. The mentioned Shellsol AB is anaros,,-=0.008 n '7 I matic fraction of the BF. l80220C. p 7.00; m 6.06;x 2.72

TABLE III Temper- H parature. tlal pres- Examples Solvent 2-alkyl- 5C.sure pr,

20 16 106... .do 10 7 101... Dlmethyl-o-phthalate. 57 45 10g.-. ..do 5045 10h Mixture M25 parts per wleght Shellsol-AB and 75 parts per welg 240 11 101. 1-phenylethanol-1 40 31 10] Mixture 0125 parts per weightl-methyl-nephthallne and 75 parts per weight2-ethylhexa 40 28 molesMoles Yield refieBOz/ Moles HzQ/ lated to hyhydro- Hi0] hydrodroqulnoneM be e we A mo K t s}; P mm x qulnone NBBOI qulnone (percent) 40.000.200 0.223 0.042 1.138 7.49 3.75 90 0.006 1.015 8.41 7.62 1.07 3.954.23 96.5 35.27 0.200 0.223 0.042 0.9194 8.21 3.11 100 0.010 0.903 8.357.36 1.07 3.31 3.54 94.5 41.20 0.9060 0.0925 0.022 0.4302 10.00 1.90 300.002 0.460 9.23 8.02 1.10 2.11 2.32 94.5 34.72 0.0950 0.0925 0.0430.2467 14.73 0.11 100 0.012 0.365 9.99 7.80 1.10 0.52 0.56 86.5 34.720.0670 0.0723 0.066 0.3151 14.73 0.11 150 0.0005 4.70 1.99 0.60 1.19 1410.248 0.252 0.322 3.63 10.00 1.90 0.015 3.75 9.38 8.72 1.01 3.19 3.2203.5 141 0.250 0.250 0.250 3.90 10.00 1.90 0.017 4.10 9.46 7.71 1.112.80 3.11 89.5 132 0.196 0.144 0.333 2.80 9.96 1.92 50 0.021 3.00 9.247.48 1.08 3.50 3.78 86.6 93 0.233 0.267 0.575 2.28 9.96 1.92 40 0.0182.41 9.42 8.08 1.05 4.28 4.60 90 30 0.170 0.170 0.212 0.586 9.47 2.21 400.012 0.617 9.02 7.26 1.09 3.38 3.67 88 EXAMPLE 1 l u 1.03 moles Na B,O/mole hydroquinone A one stage process was conducted according to themethod of examples l0 a-j with the difference that in the place ofsodium metaborate, finely divided potassium metaborate was employed(analysis figures: m gram atoms K/kg.. corresponding K moles water ofcrystallization per mole KBO Solvent: cyclohexyl acetate Autoxidant:Z-ethylanthrahydroquinone Temperature: 40C.

Water vapor partial pressure p, l 0 Gas velocity 1 500 M= 150.0; h0.330; e= 0.070; w 0.240 A==5.26;m =9.41;K= 1.36 r= 35 s; 0.005 p=5.62;m=8.79;x=8.45 u 1.00 mole KBO,/mole-hydroquinone 2.09 mole l-l OlmoleKBO, 2.09 mole H Olmole-hydroquinone yield: 96 percent of theory relatedto -hydroquinone EXAMPLE 12 A one step process was conducted accordingto the method of examples l0 a-j with the difference that in the placeof sodium metaborate, finely divided disodium tetraborate was employed(analysis figures: m gram atoms Na/kg., corresponding K moles of waterof crystallization per mole Na,B.O,).

Solvent: dimethyl-o-phthalate Autoxidant: 2-ethylanthrahydroquinoneTemperature: 40C.

Water vapor partial pressure: p 10 Gas streaming velocity 1 570 M=121.2; h 0.170; e= 0.330; w 0.205 .4 7.90; m 5.37; k= 9.53

10.7 moles H,O/mole Na B O l 1.0 moles l-l Olmole -hydroquinone yield:92.5 percent of theory related to -hydr0quinone EXAMPLES 13 a and b Aone stage process was conducted according to the method of examples l0a-j with the difference that the water vapor partial pressure p of theair was not held constant. This parameter could be changed very quickly.

When the reaction was conducted so that when the solid agglomerated toloose flakes, this was just countered by lowering of the water vaporpartial .pressure p When the solid failed to agglomerate or suchagglomerations appeared only very late, water was added to the reactionmixture by increasing p until flakes appeared which were afterwards justdissolved again by lowering of the water content of the air. Thus, bymaintaining the reaction on the verge of agglomeration, the reactionproducts formed in powdery to fine granular form; they were white andhigh yields were obtained with high reaction rates. In the place of avisual observation there could be a nephelometric measurement by aphotocell as described in the preamble of examples 8 a-d. Observationand measurement here must be put through in thin layers because of thedark color of the organic solutions. The regulation of the reactions andtheir result can be improved by setting a program for the water vaporpartial pressure p as described in example 8 ad.

After i minutes the reaction mixture was filtered. The filtratecontained s moles hydrogen peroxide per kg. The solid was washed severaltimes with benzene and finally liberated from adsorbed residues ofbenzene by a short aspiration.

The P parts of the product contained m gram atoms of sodium and x gramatoms of active oxygen per kg.

The reactions can be controlled in a manner analogous to examples 8 a-dby the gas velocity 1, but there must be considered when working on onestage that the oxidation rate is influenced by this too.

The values for the various symbols set forth above and the resultsobtained in these examples 13 a and b are set forth in the followingTable IV. V

perature of 8 C. The solution contained s moles of hydrogen peroxide, wmoles of water and e moles of 2-alkyianthraquinone per kg. A parts offinely divided sodium metaborate (analysis figures: m gram atoms Na/kg.,corresponding K moles water of crystallization per mole NaBO were addedto the solution, the intensity of the stirring being regulated such thatthe solid was distributed homogenously in the solution.

After t minutes the reaction mixture was filtered. The filtratecontained s moles of hydrogen peroxide per kg. The solid was washedseveral times with benzene and finally liberated from adsorbed residuesof benzene by a short vacuum evaporation.

The P parts of the product contained m gram atoms of sodium and x gramatoms of active oxygen per kg.

18 results obtained in these examples i4 a-f are set forth in thefollowing Table V.

. EXAMPLES l5 a-d A two stage process was conducted according to themethod of examples l4 a-f with the difference that instead of sodiummetaborate, finely divided disodium tetraborate was employed. (Analysisfigure: m gram atom Na/kg. corresponding K moles water ofcrystallization per mole Na B O,). After separating of the sodiumperborate containing product, boric acid could be obtained from thefiltrate.

The P parts of the product contained m gram atoms of sodium, b gramatoms of boron and x gram atoms of active oxygen per kg.

For the isolation of the boric acid the total filtrate was shaken outwith C, parts of water at 60C. After separation of the layers theaqueous phase was evaporated to C,, parts and then orthoboric acid wasbrought to crystallization by cooling to 5C. After filtration, washingwith ice cold water and drying B parts of white ortho boric acid wereobtained. The organic phase could be used for a new hydrogenation andoxidation reaction.

The values for the various symbols set forth above and the resultsobtained in these examples l5 a-d are set forth in the The values forthe various symbols set forth above and the following Table VI.

TABLE IV Regulation by the gas stream Temper- Water vapor oture, 6partial pres- Gas Examples Solvent 2-alkyl- C. sure PL velocityl M ho eW0. A mo K 13a Cyclohexylacetateun 2-ethyl 0-90 400 200.6 0.200 0.2000.100 4.60 8.90 2 68 13b "d0; z amyi-(mlxture of isomers)- 0-60 400200.0 0.203 0. 197 0. 160 7.96 9 86 l 99 01 l H O] M l H 0/ hYlglddremfid to Exam les pm esNa'Bor Mo es 2 use 2 yy roq none p t SE P.mm x hydroquinone N aBOi droquinone (percent) TABLE V Tempera- ExampleSolvent 2-alky1 ture,6 C. M so e W0 A 14a. Mixture 0126 parts per weightShel1so1AB" and 76 parts per weight 1, 600 0 102 0. 360 0. 340 17.78

2-ethylhexano1-1. 14b ..do 40 1,600 0.174 0.360 0.360 10.80 40 1,6000.178 0.340 0.010 6.40 40 1,600 0.181 0.340 0.660 10.60 40 160 0.2160.400 0.196 0.176 40 100 0.190 0.400 0.330 0.260

Range Yield u moles Moles Moles for We related NaB01/ H H20 wseccordsccordln to H202 mo K t as P mm 1: Hi0; NaBO; 11,0 ing to [D] to[D (percent) TABLE v1 Temperature, Examples Solvent 2-a1kyl 6 C. M so aW0 A mo 16a Mixture of 26 parts per weight "Shellsol AB" and 76 partsper weight 2-ethyl- 40 1, 600 0.188 0. 340 0. 620 8 8.3

2-ethy1hexanol-1. 16b -do .do- 40 1, 600 0.183 0. 340 0. 600 14.6 8. 34Cyclohexyl acetate.. d 40 1,600 0. 218 0.400 0.196 37. 0 0. 97 .do-- do40 1,700 0.200 0.400 0.410 21.86 8.00

Yield Range related umoles Moles Moles for we to total N azB401/ HzO/H20] w. acoordaccordi H10 2 K t se P me be 1: C-lGs H10; Na B 0 H 0ingtoIE] ingtolE (percent) EXAMPLE 16 A two stage process is conductedaccording to the method of examples l4 a-f with the difference thatinstead of sodium metaborate, a finely divided sodium perboratecontaining mixat last liberated from the residues of adsorbed benzene bya short period of aspiration.

The P parts of the product contained m gram atoms of sodium and x gramatoms of active oxygen per kg.

l d 31 r ram atoms ofNa/k 5 Like air, other gas mixtures consisting ofmolecular oxygen L was 6:11p f 7: e ":5 atoms of active and inert gasesand also oxygen alone can be used.

gram a (ms 0 g As in examples 13 a and b the results can be improved byygen/kg., corresponding K moles water of crystallization and iregulating the water concentration in the organic solutions by H gramatoms of active oxygen per mole NaBO,. The P parts the gas mixture usedfor the oxidation. of the product contained m gram atoms of sodium, 1),;gram The values for the various symbols set forth above and the atomsofboron andx gram atoms ofacuve Oxygen per results obtained in theseexam les 17 a-d a e set forth i th The values for the various symbolsset forth above and the followin Table V1" p r n 6 results obtained inthese examples 16 a and b are set forth in g the following Table Vll.EXAMPLES 1 ,,.d

EXAMPLES l7 a-d 5 A one stage process was conducted according to the 8 hStage Pmcesswtamhg Solution? ofexamples 1 method of examples l7 a-d withthe difference that in the or 2 were oxidized in the presence of solidsodium metaborate. place f Sodium metaborate, fi l divided disodium aVessel thermostaucauy malhtamed at 8 tetraborate was employed (analysisfigures: m gram atoms of Whh a Water @1 Pressure of PL Was P p through20 Na/kg., corresponding K moles water of crystallization per the fineholes the bottomone after the other A Parts of mole Na,B 0-,) and thatafter separating the sodium perboratefinely dlvlded Sodlllm metaborate(analysis figuresi 0 g Icontaining product, boric acid was obtained fromthe filtrate. gl m 0f N g-, COITePOIIdIHB K moles of Wale! of y The Pparts of the product contained m gram atoms of lization per mole NaBO,)and M parts of starting solution of sodium, b gram atoms of boron and xgram atoms of active examples 1 or 2 were placed in the vessel. Thesolution conoxygen per kg.

tained h moles 2-alkylanthrahydr0quinone, w moles water For theisolation of the boric acid alter the separation of the and e moles2-alkylanthraquinone per kg. The charging opensodiumperborate-containing mixture, the total filtrate was ing of the reactionvessel was closed, the gas delivery pipe shaken out with C parts ofwater at 60C. After separation of combined with a rotameter and the gasvelocity was regulated the layers the aqueous phase was evaporated to Cparts and to 1 liter per hour and kg. solution. !then ortho boric acidbrought to crystallization by cooling to The sodium metaboratedistributed itself quickly in the dark 15C. After filtration, washingwith ice cold water and after drysolution. After t minutes the reactionmixture was filtered. ling, B parts of white ortho boric acid wereobtained. The or- The yellow filtrate contained .9 moles of hydrogenperoxide ganic phase could be used for a new hydrogenation, oxidationper kg. The solid was washed several times with b enzene and reaction.

TABLE VII Temperature,

Example Solvent 2-a1ky1- 6 C. M so e W0 A mo=bo x0 K 16a Mixture 0125arts per weight "Shellsol AB" and 75 2-ethy1- 1, 440 0.155 0.830 0.48024.5 9.42 7.00 0.84

parts per we ght 2-ethylhexanol-1.

16 b Cyclohexyl acetate .do 160 0.280 0.400 0.210 1.89 9.80 7.04 0.65

Range Yield for wo related to moles Moles Moles we accordaccording totalH101 Example H t 51: P mm=bm x NaBOz/HzOz HzQ/NBBOz HzO/HzOz ing [F] to[F (percent) TABLE VIII H10 partial Gas 'Iemperapressure veloc- ExampleSolvent 2-a1kylture, 6 0. p1. ity l M h 0 W A m 17a Mixture 0125 partsper weight Shellsol AB" and 2-ethyl- 4o 42 200 1, 500 0.172 0.108 0. 33013.86 10.25

parts per weight 2-ethylhexanol-l.

17b Mixture of 25 parts per weight She1lsolAB" and .do 40 43 200 1,5000.172 0.168 0.350 7.56 10.25

75 parts per wei ht 2-ethylhexanol-1.

17c... Mixture 0126 parts per weight "Shellsol AB and ...do- 40 41 2001, 500 0.109 0.171 0. 300 18.50 10. 2a

76 parts per weight 2-ethylhexanol-1.

17d Cyclohexyl acetate .do 57 40 500 0.335 0.065 0.280 1.03 9. 73

' Yield related oles Moles Moles H20] w Range for W to hydroaBoz/hydroaccordin aceo d quinoue K t 51; P nm x hydroqulnone HzO/NBBO:quinone to [A5 to [A (percent) The values for the various symbols setforth above and the 66.5 percent oi the theoretical tomiiivdiygEfin' theresults obtained in these examples l8 a-d are set forth in the roduct inrelation to the originally total present H 0, or acfollowing Table IX.tive oxygen.

TABLE IX H Tempera partial v tures 6 pressure Gas Example Solvent2-alkyl- 0. PL velocity 1 M ho e W0 A mo K t 188 Dimethyl-o-phthelate2-ethyl-. 40 640 1,204 0 248 0. 252 0.200 28.10 6. 37 9.50 60 18bZ-phenylethanol d0- 40 820 1, 500 0 284 0.216 1. 450 80.3 6.97 4.78 5018ccyclohexyl acetate .do. 30 450 1,500 0 246 0.154 '0. 215 75.4 8.342.15 1811 ..d0 (1 40 30 450 1,500 0 255 0.145 0 368 27.5 8.34 2.15 60Yield 1.: moles we related o NazBioil Moles HZOI Moles H2O} cordin rangefor Wu hydroquinine P me ha x C.,/Ch B hydroquinine NazB ohydroquinineto [n aceordingto [a] (percent) EXAMPLES 19 a and b 20 EXAMPLE 21 A onestage process was conducted according to the w Y method of examples l7ad with the difference that instead of A n step Pmcess condufted acwrdmsto the memo? sodium metaboram a finely divided Sodium perbol-ate con ofexamples 13 a and b with the difference that instead of sod:-

taining mixture was employed (analysis figures: m gram 25 ""P' a finelydivided P containing atoms of Na/kg., b gram atoms of boron/kg. and xgram mlxml'e was p y l/ g o g atoms atoms of active oxygen/kg,corresponding K moles water of l/ g, 0 gr m atoms OI' I'I/Kgand x gramatoms active oxcrystallization and H gram atoms of active oxygen permole yg n/kgc responding K moles water of crystallization and H NaBO TheP parts of the product contained m gram atoms gram atoms active oxygenper mole NaB0 The P pans of the of sodium, 5,; gram atoms of boron and xgram atoms of active 3 product contained m gram atoms of sodium, b gramatoms oxygen per kg. of boron and x gram atoms of active oxygen per kg.

The values for the various symbols set forth above and the Solvent:cyclohexyl acetate results obtained in these'examples 19 a and b are setforth in k Autoxidant: Z-ethyIanthrahydroquinone Temperature: C.

the following Table TABLE X H20 Temperapartial Gas ture pressure. veloc-Example Solvent Z-alkyl- 6 0. p ity 1 M 11 e W0 A mo=bo 19a. Mixture of25 parts per weight Shellsol- 2-ethYl-- 40 46 200 1, 500 0. 175 0. 2760. 450 21. 58 9. 14

AB and 75 parts per weight Z-ethylhexanol-l. 1 b cyclohexyl acetate .do55 60 500 150 0. 224 0.176 0.205 2. 23 80 Yield oles Moles Range related8130a] Moles H1O w. for we to total hydro- H1O] hydroaccordin accordingH202 Example X0 K H t SE P mn =bn x quinone NaBO; quinone to [O to [0](P en EXAMPLE 20 regulation by the gas stream: water vapor partialpressure p A two stage process was conducted according to themm'igasvelqcny 1:500

method of examples 8 a-d with the difference that instead 00 sodiummetaborate, a finely divided sodium perborate con-} 55 71: 2 "3: 1:2taining mixture was employed (analysis figures: m gram l; :3 "184F820:atoms of Na/kg., b gram atoms of boron/kg. and x gram 5 w.,-=0.22sH=0.12 x==l2.80 atoms of active oxygen/leg, corresponding K moles waterof #213 crystallization and H gram atoms ofactive oxygen per niole '9'T1; NaB0 The P parts of the product contained m gram atoms 60 no ,i ifgfof sodium, b gram atoms of boron and x gram atoms of active 0.91 moleswater/sum of moles oxygen per kg. (active oxygen -hydroquinone) s lcyclohexyl acetate w, according to: 0.68 moles H,O/kg. gfig i izzf i g:z-ethyl-amhrahydmqmnone 6 range for W according to: 0.20 0.33 moles H0/kg. Yield: 69

percent of the theoretical total active oxygen in the product,

re ulationb the nitro en stream: water va or artial ssu g y g p p pre reIn relation to the originally present sum (active oxygen P 30 90 mm.;streamin velocit 50 N g y l 0 1m kg hydroquinone). M-ISO $2.19 r=24xl2.62 w is claimed h .224 .so .103 33220 2:53? "2:1 70 l. process forpreparing alkalrrnetal perborates in a single 8-400 x-oss m -bf ajsreaction step which comprises oxidizing with an oxygen-cona-ozos H-0.72taining gas an organic compound containing at least two 5 62 421:3x21321232 hydrogen atoms capable of being oxidized to hydrogen perox-I ml" Hm/mole. mm If). ide at a temperature below about 60: C., saidoxidation being w. according to: 0.68 mole! inc/k conducted in anorganic solvent or mixture of organic solvents rangeforw according to:0.18 0.33 moles H,0/kg. and in the presence of a solid alkali metalborate and water,

containing at least two hydrogen atoms is a member selected from thegroup of hydroquinones and aminophenols.

3. A process according to claim 1 wherein said alkali metal borate is asodium metaborate and whereinfrom 0.6 to 2.0

consisting moles of sodium metaborate are employed per mol of ltheoretically obtainable hydrogen peroxide.

4. A process according to claim 1 wherein, at the beginning of thereaction, the reaction mixture contains at least 2 moles of water permole of said solid alkali metal borate.

5. A process according to claim 1 wherein said compound,

which contains at least two hydrogen atoms, is an anthrahydroquinonesubstituted with alkyl groups having one to five carbon atoms, whereinsaid alkali metal borate is sodium metaborate employed in an amount offrom 1.0 to 2.0 mole per mole of theoretically obtainable hydrogenperoxide, wherein the reaction mixture at the beginning of the reactioncontains from 2 to 4 moles of water per mole of the sodium metaborateemployed and wherein the water concentration in the organic solution isregulated during the reaction by the moisture content and amount of saidoxygen containing gas.

6. A process according to claim 1 wherein said alkali metal perboratesare sodium perborates which contain as an average. more than 1 gramatoms of active oxygen per mole of sodium perborate product calculatedas sodium metaborate wherein said solid alkali metal borate is a sodiummetaborate and wherein the starting reaction mixture contains from0.1-0.9 moles of sodium metaborate and from 1.5 to 4 moles of water permole of theoretically obtainable hydrogen peroxide.

7. A process according to claim 6 in which the water concentration inthe organic solution is regulated during the reaction by the oxygencontaining gas forced through the reaction mixture by the amount and thewater vapor content of said oxygen containing gas.

8. A process according to claim 1 wherein said alkali metal perboratesare sodium perborates which contain as an average more than 1 gram atomsof active oxygen per mole of sodium perborate product calculated assodium metaborate, wherein said solid alkali metal borate is sodiummetaborate, wherein the starting reaction mixture contains from 0.1 to0.9 moles of sodium metaborate and from 1.5 to 4 moles of water per moleof theoretically obtainable hydrogen peroxide, and wherein the waterconcentration W in the organic solution in the starting reaction mixtureis within the range set forth by the following inequalities:

2 Ws 2 K E in which W. saturation concentration of water in the organicsolumore than 1 gram atom of active oxygen per n gram atoms of sodium, nbeing the basicity of the boric acid on which the starting borate isbased, wherein said solid alkali metal borate is disodium tetraborateand wherein the starting reaction mixture contains from 0.1 to 0.9 molesof disodium tetraborate and from 2.5 to 7 moles of water per mole oftheoretically obtainable hydrogen peroxide.

10. A process according to claim 1 wherein said alkali metal perboratesare sodium perborates which contain as an average more than 1 gram atomof active oxygen per n gram atoms of sodium, n being the basicity of theboric acid on which the starting borate is based, wherein said alkalimetal borate is disodium tetraborate and wherein the starting reactionmixture contains from 0.1 to 0.9 moles disodium tetraborate per mole oftheoretically obtainable hydrogen peroxide and wherein the waterconcentration W (moles/kg) in the organic solution of the startingreaction mixture is within the range set forth by the followinginequalities:

W, saturation concentration of water in the organic solution containingthe autoxidant and no hydrogen peroxide at the intended reactiontemperature K= water of crystallization content of the disodiumtetraborate employed.

11. A process for increasing the active oxygen content of mixturesconsisting of sodium perborates and sodium metaborate up to sodiumperborates which contain as an average more than 1 gram atom of activeoxygen per mole of sodium perborate product calculated as sodiummetaborate in a single reaction step which comprises oxidizing with anoxygen containing gas an organic compound containing at least twohydrogen atoms capable of being oxidized to hydrogen peroxide at atemperature below about 60 C., said oxidation being conducted in anorganic solvent or mixture of organic solvents and in the presence ofwater and a mixture consisting of sodium perborates and sodiummetaborate wherein the starting reaction mixture contains from 0.1 to0.9 moles of sodium perborates and sodium metaborate calculated assodium metaborate per mole of the sum consisting of the hydrogenperoxide already present in the starting sodium perborates and sodiummetaborate and that theoretically obtainable and wherein said organicsolvent or mixture of organic solvents is a solvent for the water andsaid compound but a non-solvent for sodium perborates and sodiummetaborate and wherein the water concentration W in the organic solutionof the starting reaction mixture is within the range set forth by thefollowing inequalities:

in which the solid starting mixture consisting of sodium per-. boratesand sodium metaborate is calculated as sodium metaborate:

W, saturation concentration of water in the organic solution containingthe autoxidant and no hydrogen peroxide at the intended reactiontemperature u the ratio between the moles of sodium metaborate (NaBO andthe sum of moles consisting of the hydrogen peroxide already included inthe solid starting mixture and of that hydrogen peroxide which can betheoretically obtained from the autoxidant employed K average water ofcrystallization content of the solid starting mixture per mole of sodiummetaborate H average content of hydrogen peroxide in the solid startingmixture per mole of sodium metaborate.

12. A process according to claim 11 in which the water concentration ofthe solution is regulated during the reaction by the oxygen containinggas forced through the reaction mixture by the amount and the watervapor content of the said oxygen containing gas.

13. A one-step process for the production of sodium perborates, whichcontain as an average more than 1 gram atom of active oxygen per n gramatoms of sodium, 1 being the basicity of the boric acid on which thestarting borate is based, comprising oxidizing an organic compound withat least two hydrogen atoms oxidizable with formation of hydrogenperoxide at a temperature below about 60 C. in an organic solvent or amixture of organic solvents by an oxygen containing gas and reactingsimultaneously with below 0.6 and more than 0.1

ganic solvent or the said mixture of organic taverns Being a solvent forthe water and said compound but a non-solvent for disodium tetraborateand sodium perborates.

14. A one-step process for the production of sodium perborates, whichcontain as an average more than 1 gram atom of active oxygen per mole ofsodium perborate product calculated as sodium metaborate, comprisingoxidizing an organic compound with at least two hydrogen atomsoxidizable with formation of hydrogen peroxide at a temperature belowabout 60 C. in an organic solvent or a mixture of organic solvents by anoxygen containing gas and reacting simultaneously with below 0.6 andmore than 0.1 moles of a solid sodiuml5 metaborate per mole oftheoretically obtainable hydrogen peroxide in the presence of 1.5 to 4moles water per mole of hydrogen peroxide, said organic solvent or saidmixture of organic solvents being a solvent for water and said compoundbut a non-solvent for sodium metaborate and sodium. per- 2 borates.

15. A process for the production of perborates of alkali metalscomprising forming hydrogen peroxide in a solution of an organic solventor mixture of organic solvents, said organic solvent or mixture being asolvent for water, but a non-solvent for alkali metal borate andperborate, and subsequently but directly reacting said hydrogen peroxidesolution at a temperature of l060 C. with a solid alkali metal borate inthe presence of water in an amount of from more than 1 mole to 5 molesof water per mole of alkali metal borate employed and more than 1 moleof water per mole of hydrogen peroxide present.

16. A process according to claimlS, in which the reaction mixturecontains from more than 2 moles of water up to 5 moles of water per moleof alkali metal borate.

17. A process according to claim 15, in which the reaction mixturecontains from 0.8 to 2.0 moles of alkali metal borate per mole ofhydrogen peroxide present.

18. A process according to claim 15 in which the solvent or 40 of anorganic solvent or mixture of organic solvents, said organic solvent ormixture being a solvent for the water and said compound, but anon-solvent for alkali metal borate and perborate, and subsequently butdirectly reacting said hydrogen peroxide solution at a temperature ofl0-60 C. with a solid alkali metal borate in the presence of water in anamount of from more than 1 mole up to 5 moles of water per mole ofalkali metal borate employed and more than 1 mole of water per mole ofhydrogen peroxide present.

20. A process according to claim 19 in which the compound containing atleast two hydrogen atoms is an anthrahydroquin-l one, which has assubstituents alkyl groups with one to six car-i bon atoms, in which saidalkali metal borate is a sodium metaborate, employed in an amount from0.8 to 2.0 moles per mole of hydrogen peroxide present and in which thereaction mixture contains at the beginning of the reaction from 2 to 4moles of water per mole of sodium metaborate employed.

21. A process according to claim 20 in which the water concentration inthe organic solution is regulated by passing therethrough an inert gasof predetermined amount and water content during the reaction with thesodium metaborate.

22. A two-step process for the production of sodium perborates whichcontain as an average more than 1 gram atom of active oxygen per n gramatoms of sodium, n being the basicity of the boric acid on which thestarting borate is based, como x idizing an Kigali it; compound with atleast two hydrogen atoms oxidizable with formation of hydrogen peroxidein an organic solvent or a mixture of organic solvents by an oxygencontaining gas and reacting subsequently but directly with less than 0.6and more than 0.1 moles of solid disodium tetraborate per mole oftheoretically obtainable peroxide in the presence of 2.5 to 7 moles ofwater per mole of hydrogen peroxide, the said organic solvent or thesaid mixture of organic solvents being a solvent for the water and thesaid compound but a non-solvent for the disodium tetraborate and theperborate.

23. A two-step process for the production of sodium perborates whichcontain as an average more than 1 gram atom of active oxygen per mole ofsodium perborate product calculated as sodium metaborate comprisingoxidizing an organic compound with at least two hydrogen atomsoxidizable with formation of hydrogen peroxide in an organic solvent ora mixture of organic solvents by an oxygen containing gas and reactingsubsequently but directly with less than 0.6 and more than 0.1 moles ofsolid sodium metaborate per mole of theoretically obtainable hydrogenperoxide in the presence of 1.5 to 4 moles water per mole of hydrogenperoxide, the said organic solvent or the said mixture of organicsolvents being a solvent for the water and the said compound but anon-solvent for the sodium metaborate and the perborate.

24. A two-step process for increasing the active oxygen content ofmixtures consisting of sodium perborates and sodium metaborate up tosodium perborates which contain as an average more than 1 gram atom ofactive oxygen per mole of sodium perborate product calculated as sodiummetaborate comprising oxidizing an organic compound with at least twohydrogen atoms oxidizable with formation of hydrogen peroxide in asolution of an organic solvent or a mixture of organic solvents with anoxygen containing gas, the said organic solvent or the mixture ofsolvents being a solvent for the water and the said compoundand being anon-solvent for sodium metaborate and sodium perborates, and thenreacting the ob- .tained hydrogen peroxide subsequently but directly inthe presence of water with a starting mixture of sodium perborates andsodium metaborate containing the stoichiometric equivalent of from 0.1to 0.9 moles of sodium metaborateper mole of the sum of the hydrogenperoxide contained in the solid starting mixture and the solution andwherein in the starting reaction mixture the water concentration W inthe organic solution is within the range set forth by the followinginequalities:

metaborate:

W, saturation concentration of water in the organic solution free ofhydrogen peroxide at the intended reaction temperature U the ratiobetween the moles of sodium metaborate (N aBO and the sum of molesconsisting of the hydrogen peroxide already included in the solidstarting mixture and of that hydrogen peroxide which is present in theoxidized organic solution of the starting reaction mixture K averagewater of crystallization content of the solid starting mixture per moleof sodium metaborate H average content of hydrogen peroxide in the solidstarting mixture per mole of sodium metaborate.

25. A process according to claim 24 in which the water concentration inthe organic solution is regulated during the reaction with the sodiumperborate containing mixture by the gas or the gas mixture passedthrough the reaction mixture by the amount and the water vapor contentof the said gas or gas mixture.

26. A process for the production of sodium perborates which contain asan average more than 1 gram atom of active oxygen per mole of sodiumperborate product calculated as sodium metaborate, comprising oxidizingan organic compound containing at least 2 hydrogen atoms oxidizable withformation of hydrogen peroxide in an organic solvent or a mixture oforganic solvents, the solvent or the mixture of solvents being a solventfor the water but a non-solvent for sodium metaborate and sodiumperborates, and subsequently but directly reacting the oxidation mixturewith sodium metaborate, the starting reaction mixture containing from0.1 to 0.9 moles of sodium metaborate and from 1.5 to 4 moles oi waterper mole of hydrogen peroxide.

27. A process according to claim 26 wherein said organic compoundcontaining at least 2 hydrogen atoms is an alkyl derivative ofanthrahydroquinone wherein said alkyl groups have from one to six carbonatoms.

28. A process according to claim 26 in which in the said' startingreaction mixture the water concentration W in the organic solution iswithin the range set forth by the following inequalities:

2 Ws 2 We @f iili lffifffill,

in which W, saturation concentration of water in the organic solutionfree of hydrogen peroxide at the intended reaction temperature u theratio between the moles of sodium metaborate employed and the moles ofthe hydrogen peroxide present in the oxidized organic solution of thestarting reaction mixture K water of crystallization content of thesodium metaborate employed.

29. A process according to claim 26 in which the water concentration ofthe organic solution is regulated during the reaction with the sodiummetaborate by an inert gas or gas mixture passed through the reactionmixture by the amount and the water vapor content of this said inert gasor gas mixture.

30. A process for the production of sodium perborates which contain asan average more than 1 gram atom of active oxygen per n gram atoms ofsodium, n being the basicity of the boric acid on which the startingborate is based, comprising oxidizing an organic compound containing atleast two hydrogen atoms oxidizable with formation of hydrogen peroxidein an organic solvent or a mixture of organic solvents, the solvent orthe mixture of solvents being a solvent for the water but a non-solventfor disodium tetraborate and sodium perborates, and reacting theoxidation mixture subsequently but directly with disodium tetraborate,the starting reaction mixture containing from 0.1 to 0.9 moles ofdisodium tetraborate and from 2.5 to 7 moles of water per mole ofhydrogen peroxide.

31. A process according to claim 30 in which the water conccntration ofthe organic solution is regulated during the reaction with the disodiumtetraborate by an inert gas or gas mixture passed through the reactionmixture by the amount and the water vapor content of the inert gas orgas mixture.

iijrpt cess for the production of sodium perborates which contain as anaverage more than 1 gram atom of active oxygen per n gram atoms ofsodium, n being the basicity of the boric acid on which the startingborate is based, comprising oxidizing an organic compound containing atleast two hydrogen atoms oxidizable with formation of hydrogen peroxidein an organic solvent or a mixture of organic solvents and reacting theoxidation mixture subsequently but directly with disodium tetraborate,the organic solvent or the mixture of solvents being a solvent forwater, but a non-solvent for disodium tetraborate and sodium perborates,the starting reaction mixture containing from 0.1 to 0.9 moles ofdisodium tetraborate per mole of hydrogen peroxide, and wherein thewater concentration W (moles/kg) in the organic solution of the startingreaction mixture is within the range set forth by the followinginequalitiesz 7 W6 Wofi K fTEQF: 9,

in which W, saturation concentration of water in the organic solutionfree of hydrogen peroxide at the intended reaction temperature water ofcrystallization content of the disodium tetraborate employed.

33. A two-step process for the production of sodium perborates whichcontain as an average more than 1 gram atom of active oxygen per mole ofsodium perborate product calculated as sodium metaborate comprisingoxidizing an organic compound with at least two hydrogen atomsoxidizable with formation of hydrogen peroxide in a solution of anorganic solvent or a mixture of solvents with an oxygen containing gas,the said organic solvent or the mixture of solvents being a solvent forthe water and the said compound and being a non-solvent for sodiummetaborate and sodium perborates, and then reacting the obtainedhydrogen peroxide subsequently but directly in the presence of waterwith from 0.1 to 0.9 moles of sodium metaborate per mole of hydrogenperoxide present, wherein the water content W in the organic solution ofthe starting reaction mixture is within the range set forth by thefollowing inequalities:

2. A process according to claim 1 wherein the compound containing atleast two hydrogen atoms is a member selected from the group consistingof hydroquinones and aminophenols.
 3. A process according to claim 1wherein said alkali metal borate is a sodium metaborate and wherein from0.6 to 2.0 moles of sodium metaborate are employed per mol oftheoretically obtainable hydrogen peroxide.
 4. A process according toclaim 1 wherein, at the beginning of the reaction, the reaction mixturecontains at least 2 moles of water per mole of said solid alkali metalborate.
 5. A process according to claim 1 wherein said compound, whichcontains at least two hydrogen atoms, is an anthrahydroquinonesubstituted with alkyl groups having one to five carbon atoms, whereinsaid alkali metal borate is sodium metaborate employed in an amount offrom 1.0 to 2.0 mole per mole of theoretically obtainable hydrogenperoxide, wherein the reaction mixture at the beginning of the reactioncontains from 2 to 4 moles of water per mole of the sodium metaborateemployed and wherein the water concentration in the organic solution isregulated during the reaction by the moisture content and amount of saidoxygen containing gas.
 6. A process according to claim 1 wherein saidalkali metal perborates are sodium perborates which contain as anaverage more than 1 gram atoms of active oxygen per mole of sodiumperborate product calculated as sodium metaborate wherein said solidalkali metal borate is a sodium metaborate and wherein the startingreaction mixture contains from 0.1- 0.9 moles of sodium metaborate andfrom 1.5 to 4 moles of water per mole of theoretically obtainablehydrogen peroxide.
 7. A process according to claim 6 in which the waterconcentration in the organic solution is regulated during the reactionby the oxygen containing gas forced through the reaction mixture by theamount and the water vapor content of said oxygen containing gas.
 8. Aprocess according to claim 1 wherein said alkali metal perborates aresodium perborates which contain as an average more than 1 gram atoms ofactive oxygen per mole of sodium perborate product calculated as sodiummetaborate, wherein said solid alkali metal borate is sodium metaborate,wherein the starting reaction mixture contains from 0.1 to 0.9 moles ofsodium metaborate aNd from 1.5 to 4 moles of water per mole oftheoretically obtainable hydrogen peroxide, and wherein the waterconcentration WO in the organic solution in the starting reactionmixture is within the range set forth by the following inequalities: inwhich Ws saturation concentration of water in the organic solutioncontaining the autoxidant and no hydrogen peroxide at the intendedreaction temperature u the ratio of the moles of sodium metaborateemployed to the moles of hydrogen peroxide theoretically obtainable fromthe autoxidant in the starting reaction mixture K water ofcrystallization content of the sodium metaborate employed.
 9. A processaccording to claim 1 wherein said alkali metal perborates are sodiumperborates which contain as an average more than 1 gram atom of activeoxygen per n gram atoms of sodium, n being the basicity of the boricacid on which the starting borate is based, wherein said solid alkalimetal borate is disodium tetraborate and wherein the starting reactionmixture contains from 0.1 to 0.9 moles of disodium tetraborate and from2.5 to 7 moles of water per mole of theoretically obtainable hydrogenperoxide.
 10. A process according to claim 1 wherein said alkali metalperborates are sodium perborates which contain as an average more than 1gram atom of active oxygen per n gram atoms of sodium, n being thebasicity of the boric acid on which the starting borate is based,wherein said alkali metal borate is disodium tetraborate and wherein thestarting reaction mixture contains from 0.1 to 0.9 moles disodiumtetraborate per mole of theoretically obtainable hydrogen peroxide andwherein the water concentration WO (moles/kg) in the organic solution ofthe starting reaction mixture is within the range set forth by thefollowing inequalities: in which Ws saturation concentration of water inthe organic solution containing the autoxidant and no hydrogen peroxideat the intended reaction temperature K water of crystallization contentof the disodium tetraborate employed.
 11. A process for increasing theactive oxygen content of mixtures consisting of sodium perborates andsodium metaborate up to sodium perborates which contain as an averagemore than 1 gram atom of active oxygen per mole of sodium perborateproduct calculated as sodium metaborate in a single reaction step whichcomprises oxidizing with an oxygen containing gas an organic compoundcontaining at least two hydrogen atoms capable of being oxidized tohydrogen peroxide at a temperature below about 60* C., said oxidationbeing conducted in an organic solvent or mixture of organic solvents andin the presence of water and a mixture consisting of sodium perboratesand sodium metaborate wherein the starting reaction mixture containsfrom 0.1 to 0.9 moles of sodium perborates and sodium metaboratecalculated as sodium metaborate per mole of the sum consisting of thehydrogen peroxide already present in the starting sodium perborates andsodium metaborate and that theoretically obtainable and wherein saidorganic solvent or mixture of organic solvents is a solvent for thewater and said compound but a non-solvent for sodium perborates andsodium metaborate and wherein the water concentration WO in the organicsolution of the starting reaction mixture is within the range set forthby the following inequalities: in which the solid starting mixtureconsisting of sodium perborates and sodium metaborate is calculated assodium metaborate: Ws saturation concentration of water in the organicsolution containing the autoxidant and no hydrogen peroxide at theintended reaction temperature u the ratio between the moles of sodiummetaborate (NaBO2) and the sum of moles consisting of the hydrogenperoxide already included in the solid starting mixture and of thathydrogen peroxide which can be theoretically obtained from theautoxidant employed K average water of crystallization content of thesolid starting mixture per mole of sodium metaborate H average contentof hydrogen peroxide in the solid starting mixture per mole of sodiummetaborate.
 12. A process according to claim 11 in which the waterconcentration of the solution is regulated during the reaction by theoxygen containing gas forced through the reaction mixture by the amountand the water vapor content of the said oxygen containing gas.
 13. Aone-step process for the production of sodium perborates, which containas an average more than 1 gram atom of active oxygen per n gram atoms ofsodium, i being the basicity of the boric acid on which the startingborate is based, comprising oxidizing an organic compound with at leasttwo hydrogen atoms oxidizable with formation of hydrogen peroxide at atemperature below about 60* C. in an organic solvent or a mixture oforganic solvents by an oxygen containing gas and reacting simultaneouslywith below 0.6 and more than 0.1 moles of solid disodium tetraborate permole of theoretically obtainable hydrogen peroxide in the presence of2.5 to 7 moles of water per mole of hydrogen peroxide, the said organicsolvent or the said mixture of organic solvents being a solvent for thewater and said compound but a non-solvent for disodium tetraborate andsodium perborates.
 14. A one-step process for the production of sodiumperborates, which contain as an average more than 1 gram atom of activeoxygen per mole of sodium perborate product calculated as sodiummetaborate, comprising oxidizing an organic compound with at least twohydrogen atoms oxidizable with formation of hydrogen peroxide at atemperature below about 60* C. in an organic solvent or a mixture oforganic solvents by an oxygen containing gas and reacting simultaneouslywith below 0.6 and more than 0.1 moles of a solid sodium metaborate permole of theoretically obtainable hydrogen peroxide in the presence of1.5 to 4 moles water per mole of hydrogen peroxide, said organic solventor said mixture of organic solvents being a solvent for water and saidcompound but a non-solvent for sodium metaborate and sodium perborates.15. A process for the production of perborates of alkali metalscomprising forming hydrogen peroxide in a solution of an organic solventor mixture of organic solvents, said organic solvent or mixture being asolvent for water, but a non-solvent for alkali metal borate andperborate, and subsequently but directly reacting said hydrogen peroxidesolution at a temperature of 10* - 60* C. with a solid alkali metalborate in the presence of water in an amount of from more than 1 mole to5 moles of water per mole of alkali metal borate employed and more than1 mole of water per mole of hydrogen peroxide present.
 16. A processaccording to claim 15, in which the reaction mixture contains from morethan 2 moles of water up to 5 moles of water per mole of alkali metalborate.
 17. A process according to claim 15, in which the reactionmixture contains from 0.8 to 2.0 moles of alkali metal borate per moleof hydrogen peroxide present.
 18. A process according to claim 15 inwhich the solvent or mixture of solvents is selected from the groupconsisting of alcohols having from four to 12 carbon atoms, esters ofaromatic carboxylic acids with methanol, esters of acetic acid withcyclohexanol, ketones having from five to 12 carbon atoms, alkylbenzenes and alkyl naphthalenes.
 19. A two-step process for theproduction of perborates of alkali metals comprising oxidizing with anoxygen containing gas a compound containing at lEast two hydrogen atomswhich is capable of being oxidized to hydrogen peroxide in a solution ofan organic solvent or mixture of organic solvents, said organic solventor mixture being a solvent for the water and said compound, but anon-solvent for alkali metal borate and perborate, and subsequently butdirectly reacting said hydrogen peroxide solution at a temperature of10* -60* C. with a solid alkali metal borate in the presence of water inan amount of from more than 1 mole up to 5 moles of water per mole ofalkali metal borate employed and more than 1 mole of water per mole ofhydrogen peroxide present.
 20. A process according to claim 19 in whichthe compound containing at least two hydrogen atoms is ananthrahydroquinone, which has as substituents alkyl groups with one tosix carbon atoms, in which said alkali metal borate is a sodiummetaborate, employed in an amount from 0.8 to 2.0 moles per mole ofhydrogen peroxide present and in which the reaction mixture contains atthe beginning of the reaction from 2 to 4 moles of water per mole ofsodium metaborate employed.
 21. A process according to claim 20 in whichthe water concentration in the organic solution is regulated by passingtherethrough an inert gas of predetermined amount and water contentduring the reaction with the sodium metaborate.
 22. A two-step processfor the production of sodium perborates which contain as an average morethan 1 gram atom of active oxygen per n gram atoms of sodium, n beingthe basicity of the boric acid on which the starting borate is based,comprising oxidizing an organic compound with at least two hydrogenatoms oxidizable with formation of hydrogen peroxide in an organicsolvent or a mixture of organic solvents by an oxygen containing gas andreacting subsequently but directly with less than 0.6 and more than 0.1moles of solid disodium tetraborate per mole of theoretically obtainableperoxide in the presence of 2.5 to 7 moles of water per mole of hydrogenperoxide, the said organic solvent or the said mixture of organicsolvents being a solvent for the water and the said compound but anon-solvent for the disodium tetraborate and the perborate.
 23. Atwo-step process for the production of sodium perborates which containas an average more than 1 gram atom of active oxygen per mole of sodiumperborate product calculated as sodium metaborate comprising oxidizingan organic compound with at least two hydrogen atoms oxidizable withformation of hydrogen peroxide in an organic solvent or a mixture oforganic solvents by an oxygen containing gas and reacting subsequentlybut directly with less than 0.6 and more than 0.1 moles of solid sodiummetaborate per mole of theoretically obtainable hydrogen peroxide in thepresence of 1.5 to 4 moles water per mole of hydrogen peroxide, the saidorganic solvent or the said mixture of organic solvents being a solventfor the water and the said compound but a non-solvent for the sodiummetaborate and the perborate.
 24. A two-step process for increasing theactive oxygen content of mixtures consisting of sodium perborates andsodium metaborate up to sodium perborates which contain as an averagemore than 1 gram atom of active oxygen per mole of sodium perborateproduct calculated as sodium metaborate comprising oxidizing an organiccompound with at least two hydrogen atoms oxidizable with formation ofhydrogen peroxide in a solution of an organic solvent or a mixture oforganic solvents with an oxygen containing gas, the said organic solventor the mixture of solvents being a solvent for the water and the saidcompound and being a non-solvent for sodium metaborate and sodiumperborates, and then reacting the obtained hydrogen peroxidesubsequently but directly in the presence of water with a startingmixture of sodium perborates and sodium metaborate containing thestoichiometric equivalent of fRom 0.1 to 0.9 moles of sodium metaborateper mole of the sum of the hydrogen peroxide contained in the solidstarting mixture and the solution and wherein in the starting reactionmixture the water concentration W0 in the organic solution is within therange set forth by the following inequalities: in which the solidstarting mixture consisting of sodium perborates and sodium metaborateis calculated as sodium metaborate: Ws saturation concentration of waterin the organic solution free of hydrogen peroxide at the intendedreaction temperature U the ratio between the moles of sodium metaborate(NaBO2) and the sum of moles consisting of the hydrogen peroxide alreadyincluded in the solid starting mixture and of that hydrogen peroxidewhich is present in the oxidized organic solution of the startingreaction mixture K average water of crystallization content of the solidstarting mixture per mole of sodium metaborate H average content ofhydrogen peroxide in the solid starting mixture per mole of sodiummetaborate.
 25. A process according to claim 24 in which the waterconcentration in the organic solution is regulated during the reactionwith the sodium perborate containing mixture by the gas or the gasmixture passed through the reaction mixture by the amount and the watervapor content of the said gas or gas mixture.
 26. A process for theproduction of sodium perborates which contain as an average more than 1gram atom of active oxygen per mole of sodium perborate productcalculated as sodium metaborate, comprising oxidizing an organiccompound containing at least 2 hydrogen atoms oxidizable with formationof hydrogen peroxide in an organic solvent or a mixture of organicsolvents, the solvent or the mixture of solvents being a solvent for thewater but a non-solvent for sodium metaborate and sodium perborates, andsubsequently but directly reacting the oxidation mixture with sodiummetaborate, the starting reaction mixture containing from 0.1 to 0.9moles of sodium metaborate and from 1.5 to 4 moles of water per mole ofhydrogen peroxide.
 27. A process according to claim 26 wherein saidorganic compound containing at least 2 hydrogen atoms is an alkylderivative of anthrahydroquinone wherein said alkyl groups have from oneto six carbon atoms.
 28. A process according to claim 26 in which in thesaid starting reaction mixture the water concentration W0 in the organicsolution is within the range set forth by the following inequalities: inwhich Ws saturation concentration of water in the organic solution freeof hydrogen peroxide at the intended reaction temperature u the ratiobetween the moles of sodium metaborate employed and the moles of thehydrogen peroxide present in the oxidized organic solution of thestarting reaction mixture K water of crystallization content of thesodium metaborate employed.
 29. A process according to claim 26 in whichthe water concentration of the organic solution is regulated during thereaction with the sodium metaborate by an inert gas or gas mixturepassed through the reaction mixture by the amount and the water vaporcontent of this said inert gas or gas mixture.
 30. A process for theproduction of sodium perborates which contain as an average more than 1gram atom of active oxygen per n gram atoms of sodium, n being thebasicity of the boric acid on which the starting borate is based,comprising oxidizing an organic compound containing at least twohydrogen atoms oxidizable with formation of hydrogen peroxide in anorganic solvent or a mixture of organic solvents, the solvent or themixture of solvents being a solvent for the water but a non-solvent fordisodium tetraborate and sodium perborates, and reacting the oxidationmixture suBsequently but directly with disodium tetraborate, thestarting reaction mixture containing from 0.1 to 0.9 moles of disodiumtetraborate and from 2.5 to 7 moles of water per mole of hydrogenperoxide.
 31. A process according to claim 30 in which the waterconcentration of the organic solution is regulated during the reactionwith the disodium tetraborate by an inert gas or gas mixture passedthrough the reaction mixture by the amount and the water vapor contentof the inert gas or gas mixture.
 32. A process for the production ofsodium perborates which contain as an average more than 1 gram atom ofactive oxygen per n gram atoms of sodium, n being the basicity of theboric acid on which the starting borate is based, comprising oxidizingan organic compound containing at least two hydrogen atoms oxidizablewith formation of hydrogen peroxide in an organic solvent or a mixtureof organic solvents and reacting the oxidation mixture subsequently butdirectly with disodium tetraborate, the organic solvent or the mixtureof solvents being a solvent for water, but a non-solvent for disodiumtetraborate and sodium perborates, the starting reaction mixturecontaining from 0.1 to 0.9 moles of disodium tetraborate per mole ofhydrogen peroxide, and wherein the water concentration W0 (moles/kg) inthe organic solution of the starting reaction mixture is within therange set forth by the following inequalities: in which Ws saturationconcentration of water in the organic solution free of hydrogen peroxideat the intended reaction temperature K water of crystallization contentof the disodium tetraborate employed.
 33. A two-step process for theproduction of sodium perborates which contain as an average more than 1gram atom of active oxygen per mole of sodium perborate productcalculated as sodium metaborate comprising oxidizing an organic compoundwith at least two hydrogen atoms oxidizable with formation of hydrogenperoxide in a solution of an organic solvent or a mixture of solventswith an oxygen containing gas, the said organic solvent or the mixtureof solvents being a solvent for the water and the said compound andbeing a non-solvent for sodium metaborate and sodium perborates, andthen reacting the obtained hydrogen peroxide subsequently but directlyin the presence of water with from 0.1 to 0.9 moles of sodium metaborateper mole of hydrogen peroxide present, wherein the water content W0 inthe organic solution of the starting reaction mixture is within therange set forth by the following inequalities: in which Ws saturationconcentration of water in the organic solution free of hydrogen peroxideat the intended reaction temperature u the ratio between the moles ofsodium metaborate employed and the moles of the hydrogen peroxidepresent in the oxidation mixture of the starting reaction mixture Kwater of crystallization content of the sodium metaborate employed.